The search for more stable amphiphilic resins is nowadays needed. Most of the presently known resins of this kind are based on polystyrene-PEG, polyamide, polyester or any kind of polymerized vinylic core. Their main drawback is their low chemical stability. CLEAR® (Kempe et al., (1996), J. Am. Chem. Soc., 118, 7083-7093 and (1999), U.S. Pat. No. 5,910,554) and PEGA® (Meldal, (1992), Tetrahedron Lett., 33, 3077-3080 and (1993), WO 93/16118) resins are cleaved in nucleophilic conditions (e.g. hydrolytic) as TENTAGEL® (Bayer, (1990), U.S. Pat. No. 4,908,405 and (1991), Angew. Chem. Int. Ed. Engl. 30, 113-129) in acidic media.
Resins based on primary ether bound can be used to solve some problems, however other problems remain. The presence of the polystyrene core limits the ability of the final resin to perform for example the standard Friedel-Crafts reaction and generally have low loading capacity (e.g. between 0.2 and 0.5 mmol/g to ARGOGEL®) (Labadie et al., (1997), WO 97/27226 and Gooding et al., (1999), J. Comb. Chem., 1, 113-123). Reaching higher loadings lowers the final amphiphilicity of the resin because the PEG content is decreasing proportionally (e.g. Rapp Polymere's HYPOGEL®).
Few examples of non-polystyrene-PEG based resins are known. Meldal showed the usefulness of the POEPOP resin (Renil et al., (1996), Tetrahedron Lett., 37, 6185-6188) based on PEG epoxide, and the SPOCC (Rademann et al., (1999), J. Am. Chem. Soc., 121, 5459-5466 and Meldal et al., (2000), WO 00/18823) based on PEG oxetane. Unfortunately, the use of non-conventional polymerization conditions with silicone oil and an appropriate surfactant gives a high cost manufacturing process (Grøtli et al., (2001), J. Comb. Chem., 3, 28-33). Furthermore, low loadings are obtained when higher cross-linker (CL) content is used to give better mechanical stability. EXPO3000 (Tornøe et al., (2002), Tetrahedron Lett., 43, 6409-6411) is a derivative of the former SPOCC resin based on PEG dioxetane with a silylated CL that gives a high amphiphilic resin employed in synthesis and enzymatic assays.
Recently, Oishi (Miwa et al., (2001), Polymer Journal, Vol. 33, No. 12, 927-933) showed the use of a similar oxetane based on POE as a new polymer electrolyte for lithium batteries. The polymerization process is induced by LiBF4 (or LiPF6 as further electrolyte). The final polymer is nevertheless not in a beaded form and not employed for any organic chemistry reaction. The difference between the Meldal's monomers (used for the SPOCC synthesis) and the ones presented in Oishi's article is the nature of the methyl group replaced by a ethyl one.
The use of divinylether as CL gives secondary ethers that are more susceptible to hydrolysis such as the Meldal's POEPOP. Finally, PEG diallylethers (known to give low molecular weight polymers) would give low mechanical stability polymers containing only primary ethers. The PEG vinyl ketone (that will be later reduced) offers an interesting alternative to polyether with primary ether having the right specifications.
Dörwald (Dörwald, (2000), Organic Synthesis on Solid Phase, Chap. 2. Wiley-VCH Verlag, Weinheim, Federal Republic of Germany), Meldal (Meldal, (1997), Methods in enzymology, 289, 83-104, Academic Press, N.Y.) and Côté (Côté, (2002), WO 02/40559) offer more exhaustive reviews on amphiphilic resins.
The following specifications are required for a new and low-cost amphiphilic resin:
PEG based;
Primary ethers only (chemical stability);
High loadings available;
Solid to waxy state (non-sticky);
Mechanical stability;
Normal suspension polymerization (in water);
Low manufacturing cost (commercial products).
PEG macromonomers had been investigated in the early 90' until today by several groups. Ito (Chao et al., (1991), Polym. J., Vol. 23, 1045-1052) reported the synthesis and the polymerization behavior of several styrenic and standard methacrylic PEG monomers covering most of the amphiphilic resins found today.
Yamada (Yamada et al., (1991), Makromol. Chem., 192, 2713-2722; and (1993), J. Polym. Sci. Part A: Polym. Chem., Vol. 31, 3433-3438) took another approach: the (α-PEG-methyl)acrylates. New amphiphilic monomers were synthesized and studied in copolymerization with methyl methacrylate and styrene. Unfortunately, very short methoxy-PEG chains of 1 to 3 EO were used, thus limiting the real amphiphilic potential of the final polymer. Moreover, only soluble linear polymers were reported and furthermore without any commercial uses.
Mathias reported new types of CL based on (α-Y-methyl)acrylates (where Y=malonitrile) (Tsuda, T. et al., (1993), Macromol., Vol. 26, 6359-6363); and tetraethylene glycol di(α-fluoroalkoxy-methyl)acrylate (Jariwala, C. P. et al., (1993), Macromol. Vol. 26, 5129-5136). Moreover, Mathias showed how theses short CL have the tendency to cyclopolymerize instead of “really” cross-link.
Maillard (Philippon et al., (1997) brings new approaches to synthesize macrocycles (mainly crown ethers). By the use of short PEG-acrylate and (α-PEG-methyl)acrylate (3 EO units only) that are submitted to radical reductive conditions (with Bu3SnH), several crown ethers were obtained.
Finally, no example of monomers, CL and beaded insoluble polymers based on (α-PEG-methyl)acrylates has been published (review of Yamada et al., (1994), Progr. Polym. Sci., Vol. 19, 1089-1131).
It is an object of the present invention to provide a simple monomer design to give maximum loading on the final polymerized material versus known monomers and CL (cross-linker). Usual solid supports are synthesized by the mean of monomers and CL that contain:
where:
X═H and/or CH3;
Y=EWG (electron withdrawing group) and/or aryls with anything linked to it;
Z, ZIII and ZIV=anything;
ZI, =EWG-spacer-EWG;
ZII=(EWG)2-spacer-EWG;
n=0 or 1.
It is an object of the present invention to provide the use of high percentage of CL without affecting the final loading of the resulting polymer contrary to what is presently found in the literature. As mentioned above, amphiphilic resins are using standard acrylates, methacrylates, acrylamides and/or methacrylamides where high CL content is needed to obtain a non-sticky polymer. This problem occurs also in the case of epoxide and/or oxetane based polymers.
It is an object of the present invention to provide high functionalized monomers, cross-linkers, and polymers. Bifunctional monomers or CL are known (e.g. fumaric, maleic and itaconic acid based) but each is susceptible to hydrolysis and/or nucleophilic attack. Divinylbenzene is also a bifunctional CL but no chemical fucntion is still available once polymerized.
It is an object of the present invention to provide a stable polymer which can be used further as handle, linker and/or spacer for SPPS (Solid Phase Peptide Synthesis) and SPOS (Solid Phase Organic Synthesis).
It is an object of the present invention to provide highly functionalized non hydrolysable CL.
It is another object of the present invention to provide a new type of monomer based on the use of epoxides or oxetane groups. Theses groups could be lately derivatized in other CF and/or linkers found in SPPS and/or SPOS before and/or after polymerization.
It is another object of the present invention to provide polymeric solid supports that can be used for the solid phase synthesis of peptides, oligonucleotides, oligosaccharides and in combinational and traditional organic chemistry.
It is another object of the present invention to provide resins that can be used in liquid phase synthesis, chromatography, for scavenging purposes, and for protein and reagents immobilisation.